【作者】 季明；

【导师】 高峰；

【作者基本信息】 中国矿业大学 ， 固体力学， 2009， 博士

【摘要】 本文在实验室条件下进行了灰质泥岩试件的三向自由膨胀试验,利用YAW系列微机控制电液伺服压力试验机控制系统结合美国Physical Acoustics公司的CTA-1型煤岩声电数据采集系统对不同含水率下的灰质泥岩进行了单轴压缩实验,分析了湿度场对灰质泥岩力学性质的影响。运用湿度场应力理论、弹塑性理论、损伤力学和粘弹性理论探讨了湿度条件下的灰质泥岩的本构模型。研究成果为水电工程、矿山工程、建筑工程、环境工程以及石油工程等重大工程中的岩石水力学问题提供了有益的研究资料。论文主要研究成果和创新点如下:基于湿度应力场理论,结合弹塑性力学,建立了考虑湿度对岩石材质影响的增量型弹塑性本构模型,并分别推导了等向强化模型以及随动强化模型下的弹塑性本构关系以及加卸载准则。通过对灰质泥岩的三向自由膨胀试验,研究了完全自由膨胀应变的时间效应规律,提出了膨胀稳定的时间阈值概念,并据此推导了侧限条件下膨胀应变随时间的变化规律;并根据传统的岩石膨胀理论推导了考虑时间效应的非稳定膨胀理论。并结合多孔介质基本理论,推导了考虑湿度膨胀效应的非饱和岩土介质的动态孔隙度模型。研究了含水率对岩石的力学和声发射特性的影响,实验结果表明弹性模量、抗压强度随着含水率的增加而减小,峰值应变随着含水率的增加而增大。结合损伤力学理论,探讨了单轴压缩条件下,含水岩石的损伤演变规律,并推导了考虑载荷和湿度共同作用的灰质泥岩的损伤本构模型。以西原体模型为基础,引入膨胀岩石的湿度膨胀系数,粘性衰减系数和损伤变量,综合考虑湿度效应对岩石弹性变形、粘性流动以及结构损伤的共同影响,建立了岩石湿度损伤粘弹塑性本构关系,推导了考虑湿度效应的岩石蠕变方程、卸载方程以及松弛方程,并建立了能全面反映膨胀岩石在含水状态下的粘弹塑性质的三轴蠕变理论模型。基于FLAC3D软件,以淮北煤业集团祁南煤矿82五中车场为工程背景对干燥围岩巷道无支护、有支护、含水弱化围岩巷道无支护、有支护等几种模型的蠕变特征进行数值模拟,研究了各种模型的表面位移、主应力分布、剪应力分布以及塑性区分布等规律,定性分析了水对巷道支护设计的影响,等到一些可供支护设计参考的结论。更多还原

【Abstract】 Three directions free swelling tests of calcareous mudstone specimens were conducted under laboratory conditions in this paper. By using YAW series microcomputer controlled electro-hydraulic servo compression testing machine control system combining with CTA-1 coal rock acoustic-electric data acquisition system supplied by American Physical Acoustics company, the uniaxial compression experiments on calcareous mudstone with different water content were carried out and the influence of humidity field on mechanical properties of the specimens was also analyzed. The constitutive model of the calcareous mudstone under humidity conditions was studied based on coupling equation of humidity stress field theory, elastic-plastic constitutive theory, damage mechanics and viscoelastic theory. The research results could provide helpful information for hydropower project, mining, construction, environmental and petroleum engineering on the rock hydraulics issues. The main achievements and innovative points are as follows:Based on theory humidity stress field and combined with elastic-plastic theory, elastic-plastic constitutive model of incremental type which had taken the humidity into account was found. The elastic-plastic constitutive relations and the loading-unloading criterion were derived from isotropic hardening model and kinematic hardening model.The time-effect law of full free swelling was studied through the tests of three directions free swelling. The concept of time threshold value was presented and the variation law of swelling strain versus time under laterally constrained condition was deduced hereby. By connecting with porous media theory, dynamic porosity model of unsaturated geotechnical medias which had considered humidity swelling effect was derived.By researching the effect of water content on mechanics and acoustic emission features, it was found that the elastic modulus and the compressive strength decreased with the increasing water content when peak strain showed the reverse trend. The damage evolution law of water-bearing rocks under uniaxial compression was also studied which had combined with the damage mechanics theory, and then the damage constitutive model of calcareous mudstone which had taken the loading and humidity together into consideration was deduced.The differential thermo-visco-elasto-plastic constitutive equation of rock which considers the influence of humidity on elasticity, viscosity and damage has been established based on the Nishihara rheological model by introducing humidity expand coefficient, viscosity attenuation coefficient and damage variable. Creep equation, unloading equation and Relaxation Equation of rock considering humidity effect have also been derived,and the theoretical model of multiaxial creep which can fully reflect the visco-elastic-plastic quality of swelling rock in watered state been established.Base on FLAC3D software and take 82 fifth middle yard in Qi-nan coal mine of Huai-bei coal industry group for background, numerical simulation of creep characteristics on several models of dry and moisture weaken surrounding rock roadway with and without supporting was performed, several rules of these models such as surface displacement, principal stress distribution, shear stress distribution, plastic zone distribution etc. were researched. Conclusions about the effect of water on roadway supporting design were obtained which provided a reference for supporting design.更多还原